Blower with a vibrating body having a restraining plate located on a periphery of the body

Abstract

A piezoelectric blower includes a housing, a vibrating body, and a piezoelectric element. The vibrating body includes a vibration plate, a reinforcing plate, and a restraining plate. The vibrating body forms a columnar blower chamber with the housing while holding the blower chamber therebetween from a thickness direction of the vibration plate. The vibrating body includes an outer peripheral region in contact with an area from the outermost node of pressure vibration in the blower chamber, of nodes of the pressure vibration formed by the bending vibration of the vibrating body, to an outer periphery of the blower chamber, and a center region located in an inner side portion of the outer peripheral region. The restraining plate that restrains the bending vibration of the outer peripheral region is provided in the outer peripheral region.

The invention claimed is: 
     
       1. A blower comprising:
 an actuator including a vibrating body having a first principal surface and a second principal surface and a driving body provided on at least one of the first principal surface and the second principal surface of the vibrating body to bend and vibrate the vibrating body in a vibration mode of a third or more odd order forming a plurality of vibration nodes; and 
 a housing joined to the vibrating body to form a blower chamber with the actuator and having a vent allowing an inside and an outside of the blower chamber to communicate with each other; 
 wherein the vibrating body includes a vibration plate and a restraining plate, wherein the restraining plate is joined to the vibration plate on a side opposite from the housing, 
 wherein the vibrating body includes an outer peripheral region in contact with an area from an outermost pressure vibration node in the blower chamber, among pressure vibration nodes formed by the bending vibration of the vibrating body, to an outer periphery of the blower chamber, 
 wherein the vibrating body includes a center region located in an inner side portion of the outer peripheral region, and 
 wherein the restraining plate restrains the outer peripheral region of the vibrating body. 
 
     
     
       2. The blower according to  claim 1 , wherein a rigidity of the outer peripheral region is higher than a rigidity of the center region. 
     
     
       3. The blower according to  claim 2 , wherein a thickness of the outer peripheral region is larger than a thickness of the center region. 
     
     
       4. The blower according to  claim 2 , wherein the driving body is a piezoelectric body. 
     
     
       5. The blower according to  claim 2 , wherein the vent comprises a valve to prevent gas from flowing from the outside of the blower chamber to the inside of the blower chamber. 
     
     
       6. The blower according to  claim 1 , wherein a thickness of the outer peripheral region is larger than a thickness of the center region. 
     
     
       7. The blower according to  claim 6 , wherein the driving body is a piezoelectric body. 
     
     
       8. The blower according to  claim 6 , wherein the vent comprises a valve to prevent gas from flowing from the outside of the blower chamber to the inside of the blower chamber. 
     
     
       9. The blower according to  claim 1 , wherein a shortest distance (a) from a center axis of the blower chamber to an end of an area in an inner side portion of a joint portion of the vibrating body to the housing and a vibration frequency (f) of the actuator satisfy a relation that (a)(f)=(k 0 )(c)/(2π) wherein (c) represents an acoustic velocity of gas passing through the blower chamber and (k 0 ) represents a value to satisfy a relation that a Bessel function of a first kind J 0 ′(k 0 ) is equal to 0. 
     
     
       10. The blower according to  claim 9 , wherein the driving body is a piezoelectric body. 
     
     
       11. The blower according to  claim 9 , wherein the vent comprises a valve to prevent gas from flowing from the outside of the blower chamber to the inside of the blower chamber. 
     
     
       12. The blower according to  claim 1 , wherein the driving body is a piezoelectric body. 
     
     
       13. The blower according to  claim 12 , wherein the vent comprises a valve to prevent gas from flowing from the outside of the blower chamber to the inside of the blower chamber. 
     
     
       14. The blower according to  claim 1 , wherein the vent comprises a valve to prevent gas from flowing from the outside of the blower chamber to the inside of the blower chamber. 
     
     
       15. The blower according to  claim 1 , wherein the restraining plate extends at least from the outermost pressure vibration node to an outer periphery of the housing. 
     
     
       16. A blower comprising:
 an actuator including a vibrating body having a first principal surface and a second principal surface and a driving body provided on at least one of the first principal surface and the second principal surface of the vibrating body to bend and vibrate the vibrating body in a vibration mode of a third or more odd order forming a plurality of vibration nodes; 
 a housing joined to the vibrating body to form a blower chamber with the actuator and having a vent allowing an inside and an outside of the blower chamber to communicate with each other; and 
 a restraining plate, 
 wherein the vibrating body includes an outer peripheral region in contact with an area from an outermost pressure vibration node in the blower chamber, among pressure vibration nodes formed by the bending vibration of the vibrating body, to an outer periphery of the blower chamber, 
 wherein the vibrating body includes a center region located in an inner side portion of the outer peripheral region, 
 wherein the restraining plate restrains the outer peripheral region of the vibrating body, and 
 wherein the restraining plate extends at least from the outermost pressure vibration node to the outer periphery of the blower chamber.